Is there a way where a scenario with "Thermal Load 1" and a "Thermal Load 2" can be inserted into HOMER Grid?

No, unfortunately HOMER Grid cannot model two thermal loads.  The best you can do is probably to model the electric load and one of the thermal loads in HOMER Grid, then model the second thermal load in a separate HOMER file or elsewhere, for example in Excel.  If you do not intend to serve both thermal loads with excess electricity, then that approach, although inconvenient, will be accurate.